@Jérôme Lozaïc, kudos for giving these a go but this cut still needs a fair bit more work before being added to the megapack. The edges aren't quite smooth and neither of them are in the correct dimensions.

Have a look at this thread for guidelines for cutters and video tutorials on what we expect for from our cuts.

I recommend using remove.bg for your cuts. It's a fantastic free online tool which does the heavy lifting for you by removing the background in the source image, leaving you to only rotate, crop and/or nudge the collar upwards. It's tremendously easy to use and provides fantastic quality. With it, you can go from source to cut in a couple of minutes for the vast majority of images.

Here's a couple of videos on how to use it, one when combined with Photoshop and another using photopea.com, which is a free online app so close to Photoshop that it has the same shortcuts, layout and icons 😉 If you don't have Photoshop, photopea.com is the tool I would recommend to use to tweak the draft cut produced by remove.bg. It's more powerful and versatile than GIMP and other similar tools.